The io routines have been adopted to use R printing and error routines

* src/mat.c (Mat_PrintNumber): Moved to io.c

* src/mat.c (Mat_VarPrint): Moved to io.c

* src/read_data.c (ReadCompressedCharData): Call Rprintf instead of printf

* src/read_data.c (ReadCharData): Call Rprintf instead of printf